Urinalysis (cont.)

Siamak N. Nabili, MD, MPH

Dr. Nabili received his undergraduate degree from the University of California, San Diego (UCSD), majoring in chemistry and biochemistry. He then completed his graduate degree at the University of California, Los Angeles (UCLA). His graduate training included a specialized fellowship in public health where his research focused on environmental health and health-care delivery and management.

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

red blood in the urine, also referred to as hematuria (red urine color),

liver disease (urine the color of tea), or

breakdown of muscle (orange or tea colored urine).

Certain medications may also change the color of urine. Very foamy urine may represent large amounts of protein in the urine (proteinuria).

What is urine dipstick chemical analysis?

Urine dipstick is a narrow plastic strip which has several squares of different colors attached to it. Each small square represents a component of the test used to interpret urinalysis. The entire strip is dipped in the urine sample and color changes in each square are noted. The color change takes place after several seconds to a few minutes from dipping the strip. If read too early or too long after the strip is dipped, the results may not be accurate.

Each color change on a particular square may indicate specific abnormalities in the urine sample caused by a certain chemical reaction. The reference for color changes is posted on the plastic bottle container of the urine test strips. This makes for easy and quick interpretation of the urinalysis results by placing the strip next to the container and comparing its color changes to the reference provided.

The squares on the dipstick represent the following components in the urine:

specific gravity (concentration of urine),

acidity of the urine (pH),

protein in the urine (mainly
albumin),

glucose (sugar),

ketones (products of fat metabolism),

blood, leukocyte esterase (suggestive of white blood cells in urine),

nitrite (suggestive of bacteria in urine),

bilirubin (possible liver disease or red blood cell breakdown), and

urobilinogen (possible liver disease).

Presence or absence of each of these color changes on the strip provides important information for clinical decisions.